1. Technical Field
The present application relates to a beverage bottling plant for filling bottles with a liquid beverage material having a filling machine for filling bottles, cans and similar containers as described herein below.
2. Background Information
A beverage bottling plant for filling bottles with a liquid beverage filling material can possibly comprise a beverage filling machine with a plurality of beverage filling positions, each beverage filling position having a beverage filling device for filling bottles with liquid beverage filling material. The filling devices may have an apparatus designed to introduce a predetermined volume of liquid beverage filling material into the interior of bottles to a substantially predetermined level of liquid beverage filling material. The apparatus designed to introduce a predetermined flow of liquid beverage filling material further comprises an apparatus that is designed to terminate the filling of the beverage bottles upon the liquid beverage filling material reaching the predetermined level in bottles. There may also be provided a conveyer arrangement that is designed to move bottles, for example, from an inspecting machine to the filling machine. Upon filling, a closing station closes the filled bottles. There may further be provided a conveyer arrangement configured to transfer filled bottles from the filling machine to the closing station. Bottles may be labeled in a labeling station, the labeling station having a conveyer arrangement to receive bottles and to output bottles. The closing station and the labeling station may be connected by a corresponding conveyer arrangement.
Filling valves of the prior art are equipped with gas cutoffs or gas locks. Filling valves with gas cutoffs are primarily used for the bottling of carbonated liquids that are introduced from a pressure vessel into a bottle that is connected with the filling mechanism. In the prior art, before the actual filling begins, the pressure between the bottle and the pressure vessel must be equalized so that the liquid can flow into the bottle as a result of hydrostatic pressure. During this process, the counter-pressure gas in the bottle is pushed back into the actual gas headspace of the filling bowl and is replaced by the liquid. For this purpose there is a return gas tube 11 which, with its bottom end surface, defines the boundary of the actual filling process, as soon as the liquid has reached said end surface.
Consequently, a further escape of the gas back into the pressure vessel is no longer possible. On such filling mechanisms there is a risk that the quantity of gas that is above the surface of the liquid will bubble up through the liquid duct, which is still open, and will thereby cause an after-running of the liquid that is above the valve seat. This situation can be effectively prevented by a gas cutoff that is located above the valve seat, for example.
On filling valves in which the filling level is determined essentially by a return gas tube 11, it is absolutely necessary to prevent the liquid flowing into the container from adhering to said return gas tube and to prevent it from flowing along said return gas tube 11 into the container to be filled. If the liquid should flow along the return gas tube 11 into the container, there is a risk that drops of liquid that adhere to the lower end of the return gas tube 11 can be carried along by the pre-pressurization gas that is flowing through the return gas 11 out of the container and accumulate inside the return gas tube 11, for example, as a result of which they can lead to a “sputtering” of the return gas tube 11 and ultimately to a disruption of the filling process.
To reliably prevent this situation, it has been known for some time that guide elements for the liquid, generally devices that are called screens or shields 16 can be located on the external contour of the return gas tube 11 that deflect the liquid far above the lower end of the return gas tube 11 and steer it toward the container wall. Because such return gas tubes 11 equipped with a screen 16 are expensive to manufacture, and as a rule must be changed depending on the model of bottle being used, many attempts have been made in the past to replace the screens 16 with other components. For example, in similar devices of the prior art, swirl inserts or torsion bodies have been located inside the liquid path which impart a rotational motion to the liquid, as a result of which the liquid flows into the container in contact with the inside wall of the container.
Because the use of gas cutoffs and swirl inserts or the use of gas cutoffs and return gas tubes with screens must be considered disadvantageous on account of the high costs of manufacturing, installation and maintenance, attempts have been made to combine gas cutoffs and swirl inserts.
For example, DE 41 40 524 C2 describes a thin, bell-shaped gas cutoff that can be manufactured in the form of a stamped sheet metal part, for example, in which the holes that run through said bell are oriented tangentially, so that a rotational motion is imposed on the liquid that flows through these openings.
The principal disadvantage of this device described in the prior art is that the material thickness of the bell is comparatively low. This low thickness is a disadvantage because the material thickness is equivalent to the length over which the liquid is guided, the purpose of which is to impose a rotational motion on the incoming liquid which has an essentially diffuse flow. The short length of the guidance therefore means that the new velocity vector, which comprises direction and velocity, can only be realized incompletely, especially since the liquid flows into the container only as a result of the hydrostatic pressure.
It is further disadvantageous that the bell shape of the gas cutoff requires a double deflection of the liquid, as a result of which the filling speed of the liquid is disadvantageously influenced. A gas cutoff of this type, on account of its large dimensions, also requires a great deal of space in the vertical direction, which is likewise disadvantageous for cost reasons and on account of the small amount of space available.
A comparable device was described in German Utility Model 78 11 788, in which the gas cutoff comprises an element that is in the shape of a truncated cone, the lower edge of which is formed by a comb-like structure. The slots in said comb-like structure are thereby realized so that they impart a centrifugal acceleration to the liquid as it flows into them.
Theoretically, the disadvantages cited above also apply to the device described by Utility Model 78 11 788. The manufacture of the comb-like structure described above is also very complex and expensive.